Verify that Git FS can be used when remote filesystem is offline and local clone is identified.

[jbfaden]

Bill was unable to get to the Juno orbits files on github, and it occurred to me with RBSP we had several places it would check for the files, so that there was redundancy. With github you could nicely get redundancy just by having a local clone. I should verify that this mode of operation works.

[jbfaden]

Also interesting is the TimeRangeTool's Orbit showed the error from github, so I should figure out how to safely detect that the remote server is off-line.

[jbfaden]

And for that matter I should finally figure out how to detect git filesystems, so I don't have to enumerate them.